Conventionally, non-volatile semiconductor memory devices in which memory cells are disposed at the intersections of bit lines and word lines have been known (see, for example, Patent Literature 1). A conventional memory cell comprises, for example, a floating gate capable of storing charges. In such a non-volatile semiconductor memory device, an insulation layer surrounds the floating gate of each memory cell and various types of wiring such as the bit lines and the word lines connected to the memory cells. The memory cells are insulated from each other and the various types of wiring are insulated from each other by the insulation layer.